Use of Cocoa in C++ like in Delphi - c++

Question

There is a pattern in Delphi to work with Cocoa classes. A blog about this pattern is here:
Using OS X APIs directly from Delphi
I wonder, how it works and whether it can be done with xcode in C++ too.
As example I take the function "InternalGetMACOSPath" from System.IOUtils.pas. I put excerpts of the involved code at the end of this post. The line of code that I am interested in is:
nsFile := TNSFileManager.Wrap(TNSFileManager.OCClass.defaultManager);
In essence the following would be an equivalent in C++:
NSFileManagerClass* pFManagerClass;
NSFileManager* pFManager;
// GetOCClass
void* cls = objc_getClass("NSFileManager");
pFManagerClass = Import(cls);
// Wrap
pFManager = Import(pFManagerClass->defaultManager());
I like to know whether the dummy function "Import" can be defined by use of Objective-C Runtime functions. I guess that Delphi has to use the Objective-C Runtime functions in the end too. From where else could it have the informations for the vtables?
Code snippets:
NSFileManager = interface(NSObject)
['{9736DF94-95E9-4111-8C94-82D5EFF52A81}']
function URLForDirectory(directory: NSSearchPathDirectory; inDomain: NSSearchPathDomainMask; appropriateForURL: NSURL; create: Boolean; error: PPointer): NSURL; cdecl;
...
NSFileManagerClass = interface(NSObjectClass)
['{E666ADEB-9DBE-4BF0-BEE0-5912CF9F5AB4}']
{class} function defaultManager: Pointer; cdecl;
end;
TOCImport = class(TRawVirtualClass, ILocalObject)
TOCGenericImport<C: IObjectiveCClass; T: IObjectiveCInstance> = class(TOCImport)
TNSFileManager = class(TOCGenericImport<NSFileManagerClass, NSFileManager>) end;
class function TOCGenericImport<C,T>.GetOCClass: C;
var
ClassImport: TOCImport;
ClsID: Pointer;
ITypeInfo: PTypeInfo;
CTypeInfo: PTypeInfo;
begin
ITypeInfo := TypeInfo(T);
CTypeInfo := TypeInfo(C);
ClsID := objc_getClass(MarshaledAString(ShortStrToUTF8String(#ITypeInfo^.Name)));
FClassVTable := TOCVTable.Create(CTypeInfo, False);
ClassImport := TOCImport.Create(ClsId, nil, FClassVTable);
ClassImport.QueryInterface(GetTypeData(CTypeInfo)^.Guid, FOCClass);
Result := FOCCLass;
end;
class function TOCGenericImport<C,T>.Wrap(P: Pointer): T;
var
ObjID: Pointer;
Obj: TOCImport;
ITypeInfo: PTypeInfo;
begin
ITypeInfo := TypeInfo(T);
Obj := TOCImport.Create(P, nil, GetInstanceVTable);
Obj.QueryInterface(GetTypeData(ITypeInfo)^.Guid, Result);
end;
class function TPath.InternalGetMACOSPath(const SearchedPath: NSSearchPathDirectory; const SearchMask: NSSearchPathDomainMask): string;
var
nsFile: NSFileManager;
URL: NSURL;
begin
nsFile := TNSFileManager.Wrap(TNSFileManager.OCClass.defaultManager);
URL := nsFile.URLForDirectory(SearchedPath, SearchMask, nil, true, nil);